How are waterproof porro Binoculars possible? (1 Viewer)

[John goshawk]

How does this design work. Is there an internal focussing lens that moves?
Does it impair image brightness?

Thanks John

 

[PYRTLE]

Cite a brand and model. I've seen an advert for a Fujinon but without any type of adjustable focusing sytem

 

[Pinewood]

Hello,

Independent focussing binoculars are generally waterproof.

Zeiss had an innovation for waterproofing centre focussing binoculars.: a bellows connecting the prisms to the oculars, but I have no idea how many models used it.

Yes, there are few Porro binoculars with internal focussing, including a model by Kern. It seems that internal focussing always reduces potential field of view. Internal focussing may increase chromatic aberrations.

Stay safe,
Arthur

 

[PYRTLE]

Independent focussing binoculars are generally waterproof.
Arthur

Quite a broad " generally " then Arthur. Advertised as such?
Thanks.

 

[John goshawk]

These for example.

https://www.opticron.co.uk/our-products/binoculars/adventurer-t-wp-binoculars

Or the opticron imagic WP

 

[PYRTLE]

These for example.

https://www.opticron.co.uk/our-products/binoculars/adventurer-t-wp-binoculars

Or the opticron imagic WP

Hopefully BF member Pete Gambey can reply, if still active and employed with Opticron.

 

[Binocollector]

Probably works with some gaskets inside that would need to be lubricated to keep them "waterproof" but I still wouldn't drop them directly in water.
Waterproofness is a "fleeing characteristic". Moving parts in themselves don't make it impossible but more difficult. After all -- every normal water faucet moves and will still be water tight for years. Over time the gaskets will become dry and brittle and then that's it. No more water-proofness.
Just for a little comparison -- if you use a dive watch, it is recommended that you have it checked once a year to see if it's still water-proof. Some have movable parts, like pushers for a chrono feature. Those are usually with double gaskets. Let's take the buttons on a Casio G-Shock as an example. They have double rubber gaskets and Casio used to even allow pushing buttons under water -- they however changed the manuals for these at some point, not necessarily because of failure of the gaskets but probably to simply have less warranty claims.
And waterproof porros are usually a bit harder to focus as there is more resistance to the focuser. But it's not at all impossible or only achievable with internal focusing or individual focusing. After all -- individual focus also has moving parts that need gaskets.

 

[NDhunter]

Minox has had waterproof, internal focusing binoculars for many years. Also Steiner makes waterproof, internal focusing.

This would not affect brightness at all, just a design preference.

 

[John goshawk]

Minox has had waterproof, internal focusing binoculars for many years. Also Steiner makes waterproof, internal focusing.

This would not affect brightness at all, just a design preference.

It's another piece of glass, so would that in itself not reduce light throughput.

 

[NDhunter]

I'm not sure about how many lenses, have you a diagram ?
It is an interesting topic.
Jerry

 

[John goshawk]

I'm not sure about how many lenses, have you a diagram ?
It is an interesting topic.
Jerry

Im just thinking about the extra internal piece of focussing lens roof binos have.

 

[John goshawk]

Seen on right here.
Cheers John

 

[Richard D]

The Swarovski Habichts are waterproof to 4m depth and transmission at 96% makes them amongst the brightest binoculars available for their objective size - the waterproofing does make focusing a lot stiffer than average.

 

[wllmspd]

APM 10x50ed and siblings IPX7, but these are individual focus. APM ED Apo 10x50 Magnesium Series Binoculars

Peter

 

[PHA]

Hi,

Swarovski Habicht are waterproof to 4m since at least 20 years ago....I once call Swarovski asking about how would this possible. The person who answer said the ocular tubes were strongly sealed (that is the reason for the more force needed to moves the focusing weel) and when moving out/in the oculars at focusing, the pressure inside moves up and down a little...
Anyway, I have had 3 sealed Habichts and ALL of them performed flawlessly in harsh conditions down here!!

 

[Pinewood]

Quite a broad " generally " then Arthur. Advertised as such?
Thanks.

Hello Pyrtle,

Individual focus binoculars are typically made for militaries, for navies and for hunters, all of whom expect some lever of integrity against spray or shallow water. The manufacturers specifications will provide how much protection. Since the word "waterproof" is a little vague, expect to read something like "water resistant to 3m." An exception might be the large binoculars used by some amateur astronomers, which are not expected to be used in the rain.

Stay safe,
Arthur

 

[wllmspd]

My 70mm APM are sealed and have just given very nice, very wide views birding at Slimbridge WWT today. They are individual eye focus, which takes a little practice.

Peter